Which spelling words should students master in order to communicate well in writing? There are numerous sources from which teachers may choose spelling words to use and teach. This paper discusses five such sources: the basal spelling textbook; words based on research studies; individualized spelling; words taken from subject matter units of study; and spelling words already mastered. Finally, the paper briefly outlines 10 characteristics of a forward-looking spelling program. (Contains 10 references.) (SR)